ok… i know that i’ve posted this before but here goes….

Mavic Deemax rims. Maxxis HRII Exo tyres.

tried running tubeless a few times now and each time i’m able to get the tyre to burp when hopping around in a field.

as i understand it UST rims have a different shape to standard rims, but what is different about them? and how can i make them “standard” so that they work with my non-UST tyres?

if people are saying that they can run non-UST tyres with UST rims and not have any problems then i can only assume that they are not riding particularly rough trails.

any pointers greatly appreciated.

cheers

J

My HR2 Exo 2.4 works fine on a Crossmax SX, and I’ve ridden it on some very rough and rocky trails in the Lakes.

It gave the loudest seating “bang” I’ve ever heard too, like someone was shooting at me. Did yours do that?

how can i make them “standard” so that they work with my non-UST tyres?

yet you want to run those non-UST tyres, tubeless? bizarre

the rims are already ‘shelved’ if you want to stop the ‘burping’ you need tighter tyres, so UST tyres or higher pressures, or keep trying different makes/models till you find something toit loike a tiger.

oh yeah, troll!

you a troll or me a troll?

you can run non-UST tyres without a tube. there was a thread singing the praises of Maxxis Exo being run tubeless a while back, hence my purchase of the HRIIs.

@ chaka…. yes, the tyre popped/banged when i pumped them up. i made a ghetto inflator bottle and then pumped the tyres up to 70psi, although the popping occured around 50psi. the milk bubbled for a few minutes and then i left them for a few hours, turning the wheels occasionally, before going for a short ride.

what am i doing wrong? (other than running UST rims?)

I’ve run non ust tyres both tubeless and non tubeless (i.e. with a tube) on my 3 pairs of Deemax rims and hammered them on DH trails, so not sure why you’re having a problem? The only tyres that wouldn’t stay inflated are Conti’s and that’s because the sidewalls leak, I managed to seal the beads, but they then deflated over time!!

I put some extra latex in non ust tyres and they eventually seal after a bit of bead leakage.

I ‘soap’ the bead before inflation using washing up liquid or tyre fitters ‘bead wax’ which aids seating.

What pressures are you managing to ‘burp’ your tyres at? I run as low as 18psi on mine in wet / technical and on rough tracks such as Fort William I usually run at 25 – 30psi and have never had a problem.

The only way to stop non UST tyres burping on UST rims is to run a rimstrip in addition to it, to make the tyre a tighter fit.

Which UST rims have you got? If they’re 819’s you need a Stans Olympic rimstrip, if they’re 823’s then you’ll want a Stans Flow rimstrip.

Best bet though is proper UST tyres. I’ve tried all sorts of tubeless combinations, it’s the tyres that make the difference not the rims, UST rims are merely more convenient to setup tubeless than normal rims (though a PITA to build in comparison).

burped the rear at about 25psi. once when landing a small hip jump. once when hoping from side to side (i was trying to see whether the tyre would burp). once when riding full pelt and turning sharply….

i don’t want to have to buy another set of tyres as i’m happy with how the HRIIs ride (with tubes!).

as i understand it the space below the lip of the rim is larger on a UST rim. would laying a few strips of gaffa in this space help make the fit tighter?

@ mboy… Deemax rims.

you can run non-UST tyres without a tube. there was a thread singing the praises of Maxxis Exo being run tubeless a while back,

some people can, with some tyres, on some rims, under some conditions.

if you meet each of those four criteria, its fine, any less than four and you might experience some problems inflating, sealing or holding air.

hth

my limited experience of maxxis EXOs (Advantage 2.1s) was that they had a pretty loose bead, one blew off a crest rim at 45psi. IMO too loose to trust, I gave them to a friend to run with tubes

I ran a non-UST tyre tubeless on UST rims once.
I suspect it contributed to my broken collarbone. The tyre certainly wasn’t on the rim any more, once I picked myself and the bike up.

@ mboy…. do i need a strip or can i “ghetto” it with gaffa or such like?

I don’t like the gaffa method cos it’s not as flexible as a rubber strip. A rubber strip will actually flex with the tyre, which helps to prevent burping. Bulking it up with gaffa tape will help provide a stronger seal, but I don’t think its as reliable.

It will be cheap and easy for you to try it though, so give it a go first see if it’s for you perhaps.

I think it is the EXO tyres that are the problem not the fact they are non UST. I have had problems with EXO Ardents all getting blown off the rims on either Haven or SX rims. In the last two years I have never had a single problem with non EXO Maxxis tyres getting blown of the rim or burping. I also ride alot or rocky stuff.

I few of my mates have had the same problems with EXO’s and have all gone back to standard Maxxis run tubeless.